Surface treating appliances such as vacuum cleaners are well known. The majority of vacuum cleaners are either of the “upright” type or of the “cylinder” type (also referred to canister or barrel machines in some countries). An upright vacuum cleaner typically comprises a main body containing dirt and dust separating apparatus, a pair of wheels mounted on the main body for maneuvering the vacuum cleaner over a floor surface to be cleaned, and a cleaner head mounted on the main body. The cleaner head has a downwardly directed suction opening which faces the floor surface. The vacuum cleaner further comprises a motor-driven fan unit for drawing dirt-bearing air through the suction opening. The dirt-bearing air is conveyed to the separating apparatus so that dirt and dust can be separated from the air before the air is expelled to the atmosphere. The separating apparatus can take the form of a filter, a filter bag or, as is known, a cyclonic arrangement.
In use, a user reclines the main body of the vacuum cleaner towards the floor surface, and then sequentially pushes and pulls a handle which is attached to the main body of the cleaner to maneuver the vacuum cleaner over the floor surface. The dirt-bearing air flow drawn through the suction opening by the fan unit is conducted to the separating apparatus by a first air flow duct. When dirt and dust has been separated from the air flow, the air flow is conducted to a clean air outlet by a second air flow duct. One or more filters may be provided between the separating apparatus and the clean air outlet.
An example of an upright vacuum cleaner with improved maneuverability is shown in GB 2 422 094. This upright vacuum cleaner comprises a barrel-shaped rolling assembly located at the lower end of the main body for engaging the floor surface to be cleaned, and which rolls relative to the main body for allowing the main body to be rolled over the floor surface using the handle. The rolling assembly is rotatably connected to arms which each extend downwardly from a respective side of the base of the main body. A yoke connects the cleaner head to the main body. The yoke is pivotably connected to the main body, whereas the cleaner head is connected to the forward, central part of the yoke by a joint which permits the yoke to be rotated relative to the cleaner head. These connections allow the main body to be rotated about its longitudinal axis, in the manner of a corkscrew, while the cleaner head remains in contact with the floor surface. As a result the cleaner head may be pointed in a new direction as the main body is rotated about its longitudinal axis. As the main body is pushed over the floor surface using the handle, the vacuum cleaner moves forward along the direction in which the cleaner head is pointed, thereby allowing the vacuum cleaner to be smoothly and easily maneuvered over the floor surface.
The main body of the vacuum cleaner houses separating apparatus for separating dirt from a dirt-bearing air flow drawn into the cleaner head. To increase the stability of the vacuum cleaner, and to make efficient use of the space within the rolling assembly, the motor-driven fan unit for drawing dirt-bearing air into the suction opening is located within the rolling assembly.
The vacuum cleaner comprises a stand for supporting the main body when it is in an upright position. The stand comprises a pair of floor engaging wheels located at the base of the stand. The stand is moveable between a supporting position and a retracted position to enable the vacuum cleaner to be maneuvered over a floor surface. The stand is released from its supporting position by the operation of a pedal located adjacent the stand. As the stand is rotated from its supporting position towards its retracted position, the stand engages an actuator which moves relative to the main body. The movement of the actuator causes a spring to move the stand to its retracted position.
The actuator also serves to retain the yoke in a fixed position relative to the main body when the stand is in its supporting position. This can enable the cleaner to be reclined backwards on to the wheels of the stand for transport, for example, between rooms without the yoke and the cleaner head drooping downwardly towards the floor surface, and thereby impairing the movement of the vacuum cleaner. In the event of an impact on the cleaner head during transport, the actuator is arranged to rotate relative to the stand to release the yoke for movement about the main body, while the stand remains retained in its supporting position through the non-operation of the pedal by the user. The force required to rotate the actuator relative to the stand can tend to be relatively high, and so there is a risk that the force of the impact may be sufficient to damage the cleaner head but insufficient to move the actuator so as to release the yoke for movement relative to the main body.